<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<style>
.dabox{
	width:400px;
	height:400px;
	border:20px solid #000;
	}
.dabox div{float:left;}
.orange{width:200px;height:100px; border-bottom:100px solid orange;}
.blue{width:200px;height:200px; background:blue;}
.yellow{width:200px;height:200px; background:yellow;}
.green{width:200px;height:200px; background:green;}
</style>
</head>

<body>
<div class="dabox">
	<div class="orange"></div>
    <div class="blue"></div>
    <div class="yellow"></div>
    <div class="green"></div>
</div>
</body>
</html>
